filmcraft/CLAUDE.md

FilmCraft — instructions for agents

FilmCraft is a clean-room, open-source, pure-Rust non-linear video editor targeting Adobe Premiere Pro parity (and beyond). Native on macOS, Windows, Linux; web via WASM. Sibling of ../photocraft (Photoshop), ../printcraft (Acrobat) and ../drawcraft (Illustrator), with the same conventions.

Start every session here

1. Read plan/STATUS.md (current milestone, next unchecked task, blockers).
2. Read the task in plan/execution-plan.md §3, the relevant section of plan/architecture.md, and the README/docs of the crate you touch. Visual/behaviour reference: plan/premiere/.
3. Follow the autonomous operation protocol (plan/execution-plan.md §7). Don't stop to ask unless §7 lists the decision as the user's.

plan/ is gitignored (local-only).

Non-negotiables

• Clean-room. Never read/disassemble anything inside Adobe app bundles (names/listings only). Never copy Adobe icons, presets, LUTs, fonts. Never copy GPL/LGPL/AGPL code (FFmpeg, x264, x265, MLT, Kdenlive, Shotcut, Olive, LAME…). ffmpeg/ffprobe run only as external test oracles / fixture generators — never linked or shipped.
• Pure Rust in the product. OS media APIs only via Rust bindings in crates/platform, optional, behind traits.
• Layering (plan/architecture.md §3, enforced by cargo xtask layers): nothing below L5 depends on egui/eframe/winit/rfd/cpal. L0 codec/container crates depend only on filmcraft-bitstream.
• Exact time: all time is filmcraft_time::Tick (254 016 000 000/s). Never use f64 seconds for edit math.
• Everything is a command (crates/engine): id, label, menu path, shortcut, params, enabled(), run(). UI, CLI, control channel and MCP all dispatch by id.
• Everything is agent-drivable: every interactive widget registers an automation id; UI state is serde so the control channel can read/set it.
• Quality gates before every commit: cargo fmt --check, cargo clippy --workspace --all-targets -- -D warnings, cargo test --workspace, cargo xtask layers, cargo xtask wasm (L0–L5 changes).
• Commits: one task id per commit (M2.4: CABAC residual decoding). Only green states. End messages with the attribution line required by the environment.

Running and looking at the app

• cargo run -p filmcraft -- --control 9876 opens the desktop app with the JSON-lines control server (see docs/control-protocol.md).
• For UI work, look at the result: drive via the control channel and take ui.screenshot, compare with plan/premiere/screenshots/.
• Parallel agents: separate git worktrees and CARGO_TARGET_DIR=target/agent-<name>; keep every Cargo.toml valid at all times (the crates/* glob means one broken manifest breaks everyone).
• Test fixtures: generate with ffmpeg into target/fixtures/ (never commit media).